A randomized open-label controlled trial of chlorhexidine-alcohol vs povidone-iodine for cesarean antisepsis: the CAPICA trial

Background: Identification of optimal surgical site antisepsis preparations may reduce cesarean-related surgical site infections. Two recently published investigations examined efficacy of chlorhexidine-alcohol and iodine-alcohol preparations. No previous randomized controlled trial has compared chlorhexidine-alcohol to povidone-iodine aqueous scrub and paint in reduction of cesarean-related surgical site infection.

Objective: The purpose of the study was to determine if chlorhexidine-alcohol would result in fewer surgical site infections than povidone-iodine when used as skin antisepsis preparation prior to cesarean delivery.

Study design: This study was a single-center pragmatic randomized controlled trial at an urban tertiary care institution to compare chlorhexidine-alcohol 26-mL single-step applicator to povidone-iodine aqueous scrub and paint 236-mL wet skin tray as preoperative skin antiseptic preparation for women undergoing cesarean delivery. Patients were eligible for study participation if they could provide informed consent in English or Spanish, were ≥18 years of age, did not have clinical chorioamnionitis, were unlikely to be lost to follow-up, and had no sensitivities to chlorhexidine, betadine, or iodine. Treatment was assigned by computer-generated simple 1:1 randomization immediately before skin preparation. The primary outcome was surgical site infection occurring within 30 days of cesarean delivery including ≥1 of: superficial or deep surgical site infection, or endometritis, according to Centers for Disease Control and Prevention definitions. Analysis was by intent to treat. Categorical outcomes were compared using Fisher exact test. The Wilcoxon rank-sum test was performed for continuous outcomes. This trial was institutional review board approved and registered at ClinicalTrials.gov (NCT02202577).

Results: In all, 932 subjects (461 assigned to chlorhexidine-alcohol, 471 assigned to povidone-iodine) were randomized from February 2013 through May 2016. Rate of follow-up evaluation after 30 days was 99% (455) in the chlorhexidine-alcohol group and 97% (455) in the povidone-iodine group. Surgical site infection occurred in 29 (6.3%) of the chlorhexidine-alcohol group and 33 (7.0%) in the povidone-iodine group (P = .38). The rates of individual components of the primary outcome were as follows: superficial surgical site infection (4.6% v 5.5%; P = .55), deep surgical site infection (0.0% v 0.4%; P = .50), and endometritis (1.7% v 1.1%; P = .42) in chlorhexidine-alcohol vs povidone-iodine arms, respectively. All results were similar in per protocol analysis.

Conclusion: Preoperative antiseptic skin preparation with chlorhexidine-alcohol 26-mL single-step applicator before cesarean did not result in less frequent surgical site infection when compared with povidone-iodine aqueous scrub and paint 236-mL wet skin preparation tray. Povidone-iodine should still be considered as acceptable for preoperative surgical site antisepsis for cesarean delivery.